Float operator



y 1956 c. A. SCHAEFER 2,747,043

FLOAT OPERATOR Filed Feb. 6, 1955 I N VEN TOR. C dr/ \SC/Zdefe 7.

United States Patent FLOAT OPERATOR Carl A. Schaefer, Milwaukee, Wis., assignor to Square D Company, Detroit, Mich., a corporation of Michigan Application February 6, 1953, Serial No. 335,535 9 Claims. (Cl. 200-84) This invention relates to an actuating system for float switches or the like.

One object of the present invention is the provision of a new and improved actuating system for float switches of inexpensive construction and in which maintenance is minimized.

Another object of the present invention is a system in accordance with the preceding object which is reliable in operation and will not become water-logged.

A further object is the provision of a system in accordance with the preceding objects which possesses excellent stability despite agitation of the liquid with which it is associated.

Other objects and features of the invention will be readily apparent to those skilled in the art from the specification and appended drawing illustrating certain preferred embodiments in which:

Figure 1 is a side view of the system of the present invention having certain parts shown in section to facilitate the explanation thereof.

Figure 2 is an enlarged sectional view of the biasing means illustrated in Figure 1.

The system of the present invention is illustrated in Figure 1 in which there is shown a switch 1 which is mounted by bolts to a support 3. To actuate switch 1 there is provided an operator 4. The casing of switch 1 is provided with a flange 5 having an opening therein through which projects a bolt 6 which is connected by means of nut 7 to a biasing spring 8, as illustrated in Figure 2. Spring 8 is connected to the operator 4 by means of cotter pin 9.

One extremity of operator 4 is connected to a chain or cable 11 which has its opposite end connected to an inverted, open bottom cup 12. The lower section of cup 12 is provided with a transverse pin 13 to which one end of a chain or cable 14 is connected. The opposite end of the chain 14 carries a weight 16 of a material having a specific gravity greater than that of the liquid whose level is to be controlled by the associated switch 1. The end of cable 14 associated with the weight 16 extends through a channel 15 therein and is secured by a washer 17.

In Figure 1 the dotted line A indicates the high level of the controlled liquid while the dotted line B indicates the low level. The full line positions illustrated in Figure 1 are those which the parts occupy when the liquid is at the level A, while the dotted line positions indicate the positions occupied when the liquid is at the level B. The switch 1 is of the type commonly employed in float systems having an internal overcenter mechanism biasing the operator 4 toward whichever of its two stable positions it occupies. A switch of this general type is shown and described in the patent to G. A. Lennholm, No. 2,314,995 issued March 30, 1943. In that patent, the casing of the switch is not provided with a flange 5, but it will be obvious that such flange may either be added to such switch casing or be part of a separate member as desired.

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In the operation of the system of the present invention, the bolt 6 is adjusted so that the spring 8 applies an upward bias to the operator 4 of such nature that the operator 4 will remain in the full line position illustrated in Figure 1 until the liquid whose level is to be controlled falls below the low position. In other words, the switch mechanism and spring 8 will support the weight of the inverted cup 12, the weight of chains 11 and 14, and part, but not all, the weight of the bottom member 16. As the liquid level falls below the low position, the effective weight of weight 16 is increased so that the upward bias applied to the operator 4 is overcome whereby it snaps to the dotted line position illustrated in Figure 1. In this position a pump (not shown) associated with the switch 1 ceases to operate it on sump service or starts up if on tank service and the liquid begins to increase in depth. As its level moves from the low position toward the high position it eventually moves above the bottom of the cup 12, trapping air inside. When the liquid level gets to the high position, the buoyancy of the cup and the bias of spring 8 become suflicient to overcome weight 16 and the internal bias of the switch 1 whereby the operator 4 moves back to the position illustrated in full lines in Figure 1. Upon such occurrence, the pump associated with switch 1 is again controlled to eifect a lowering of the liquid from the high position toward the low position, and the cycle is repeated.

it will readily appear that the system of the present invention is of minimum cost as no expensive sealed floats are necessary, nor are any guides or stops required. Furthermore, the elements 12 and 16 of the present invention can be of such nature that corrosion is substantially eliminated. In addition, the positions of the cup 12 and the weight 16 in relation to the chains 11 and 14 may be readily changed, and the bias applied by spring 8 is easily adjustable. Furthermore, by concentrating most of the weight of the system of the present invention in the weight 16, this system is of excellent stability despite agitation of the controlled liquid.

It will be seen that as the level of the liquid leaves the bottom of cup 12, it will be entirely emptied and then rescaled by the liquid itself as it again rises. This avoids any possibility of water-logging such as might occur in the case of sealed hollow balls which might eventually fill with liquid through minute openings.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

What is claimed is:

1. A float operated switch device for controlling the level of a liquid comprising an electric switch, an operator for operating said switch having two stable positions, biasing means for biasing said operator toward one of its stable positions, a plurality of counter-biasing means for biasing said operator toward the other of its stable positions comprising a suspended weight having an overall specific gravity greater than that of the controlled liquid and an inverted cup, and means mechanically interconnecting said cup and said weight to said operator with said cup disposed between said operator and said weight.

2. A float operated switch device for controlling the level of a liquid comprising an electric switch, an operator for operating said switch having two stable positions, biasing means for biasing said operator toward one of its stable positions, a plurality of counter-biasing means for biasing said operator toward the other of its stable posi Patented May 22, s

tions comprising a suspended weight having an overall specific gravity greater than that of the controlled liquid and an inverted cup, means for connecting the bottom of said cup to said operator and for connecting the open portion of said cup to said weight, said cup being between said weight and said operator.

3. A float operated switch device for controlling the level of a liquid comprising an electric switch, an operator for operating said switch having two stable positions, biasing means for biasing said operator toward one of its stable positions, a plurality of counter-biasing means for biasing said operator toward the other of its stable positions comprising a solid, suspended weight formed of material having a specific gravity greater than that of the controlled liquid and an inverted cup, flexible means mechanically interconnecting said operator and the closed portion of said cup and other flexible means connecting said weight to said cup, said cup being disposed between said weight and said operator.

4.'A float operated switch device for controlling the level of a liquid comprising an electric switch, an operator for operating said switch having two stable positions, adjustable biasing means for applying a bias of predetermined degree to said operator for urging it toward one of its stable positions, a plurality of counter-biasing means for biasing said operator toward the other of'its stable positions comprising a solid, suspended weight formed of material having a specific gravity greater than that of the controlled liquid and an inverted cup, and flexible means mechanically interconnecting said operator and the closed portion of said cap and other flexible means connecting said weight to said cup.

5, A float operated switch device for controlling the level of a liquid comprising an electric switch, an operator for operating said switch having two stable positions, said responsive means being of the type having means for urging said operator toward whichever stable position it occupies, adjustable spring means for biasing said operator toward one of its stable positions with a predetermined force, a plurality of counter-biasing means for urging said operator toward the other of its stable positions comprising a cup-shaped member and a suspended weight having an overall specific gravity greater than that of the controlled liquid, flexible means for connecting the bottom portion of the cup-shaped member to said operator whereby the open portion of said cup-shaped member is directed toward the bottom of the controlled liquid, and flexible means interconnecting said weight and the open portion of said cup-shaped member whereby said weight is immersible on variation in the level of the controlled liquid.

6. A float operated switch device for controlling the level of a liquid comprising a switch, an operator for operating said switch having two stable positions, said switch being of the type having means for urging said operator toward whichever stable position it occupies, adjustable spring means for biasing said operator toward one of its stable positions with a predetermined force, a plurality of counter-biasing means for urging said operator toward the other of its stable positions comprising a cup-shaped member and a solid, suspended weight formed of material having a specific gravity greater than that of the controlled liquid, means for connecting the bottom portion ofthe cup-shaped member to said operator whereby the open portion of said cup-shaped member is directed toward the bottom of the controlled liquid, and means interconnecting said weight and the open portion of said cup-shaped member whereby said weight is immersible on variation in the level of the controlled liquid.

7. A float operated switch device for controlling the level of an associated pool of water comprising a switch, an operator for operating said switch having two stable positions, said switch being of the type having means for urging said operator toward whichever stable position it occupies, adjustable spring means for biasing said operator toward one of its stable positions with a predetermined force, a plurality of counterbiasing means for urging said operator toward the other of its stable positions comprising a cup-shaped member and a solid-suspended weight formed of material having a specific gravity greater than 1, flexible means for connecting the exterior surface of the bottom portion of the cup-shaped member to said operator whereby the open portion of said cup-shaped member is directed toward the bottom of the pool of water, and flexible means interconnecting said weight and the open portion of said cup-shaped member whereby said weight is immersible on variation in the level of the pool of water.

8. A float operated switch device for controlling the level of a liquid comprising an electric switch, an operator for operating said switch having two stable positions, biasing means for biasing said operator toward one of its stable positions, a plurality of counter-biasing means collectively biasing said operator toward the other of its stable positions and at least one of said plurality being operable to counteract the bias of said plurality, said counter-biasing means comprising a suspended weight having an overall specific gravity greater than that of the controlled liquid and an inverted cup, and means mechanically interconnecting said cup and said weight to said operator with said cup disposed between said operator and said weight.

9. A float operated switch device for controlling the level of a liquid comprising a switch, an operator for operating said switch having two stable positions, said switch being of the type having means for urging said operator toward whichever stable position it occupies, adjustable spring means for biasing said operator toward one of its stable positions with a predetermined force, a plurality of counter-biasing means for urging said operator toward the other of its stable positions comprising a cup-shaped member and a solid suspended weight formed of material having a specific gravity greater than that of the controlled liquid, means for connecting the bottom portion of the cup-shaped member to said operator whereby the open portion of said cup-shaped member is directed toward the bottom of the controlled liquid, means interconnecting said weight and the open portion of said cup-shaped member whereby said weight is immcrsible on variation in the level of the controlled liquid, said cupshaped member operable to support said weight in one fluid level to permit said spring means to bias said operator into one stable position and operative as a weight in another fluid level to counteract said spring bias to position said operator in its other stable position.

References Cited in the file of this patent UNITED STATES PATENTS 841,334 Mower et al. Jan. 15, 1907 842,554 Johnson Jan. 29, 1907 2,642,507 West June 16, 1953 2,646,067 Smith July 21, 1953- 

